Lamp harp swivel

ABSTRACT

An improved swivel for use in mounting a lampshade on the wire frame of a lamp harp which swivel is formed of a resiliently flexible solid resinous material and comprises a base, a stud extending outwardly from one face of said base for attachment of the lampshade thereto and a channel extending across the opposite face of said base and dimensioned to accommodate the wire of said frame, the areas of said one face on opposite sides of said channel being inclined towards each other whereby pressure applied to said inclined surfaces by clamping of the lampshade on said stud releasably closes said channel into tight gripping engagement with said wire accommodated therein.

United States Patent [72] Inventors John Steyr 15 Newberry Lane, Downsview; Ernest Topler, 526 Glen Grove Rd., Toronto, Ontario, both of Canada [21 Appl. No. 4,268

[22] Filed Jan. 20, 1970 [45] Patented Oct. 19, 1971 [54] LAMP HARP SWIVEL 3,176,359 4/1965 Ward .1: 24/73 Primary Examiner-Reinaldo P. Machado Assistant Examiner-Andrew V. Kundrat Attorney-Cushman, Darby & Cushman ABSTRACT: An improved swivel for use in mounting a lampshade on the wire frame of a lamp harp which swivel is formed of a resiliently flexible solid resinous material and comprises a base, a stud extending outwardly from one face of said base for attachment of the lampshade thereto and a channel extending across the opposite face of said base and dimensioned to accommodate the wire of said frame, the areas of said one face on opposite sides of said channel being inclined towards each other whereby pressure applied to said inclined surfaces by clamping of the lampshade on said stud releasably closes said channel into tight gripping engagement with said wire accommodated therein.

PATENTEDum 1 9 mn FlG.l

2 5 E 0 TP H V 0 NT 4 M5 m 3 F E 2 m F LAMP HARP SWIVEL The present invention relates to a lamp harp and in particular to an improved swivel for clamping a lampshade on the wire frame of said lamp harp.

In conventional commercial lamp harps such as that disclosed for example in Canadian Pat. No. 402,421 issued Jan. 20, 1942 to Kornell Berger, the lampshade is held in position on the lamp harp by means of a swivel structure comprising a plurality of parts including a metal lampshade stud e.g. a screw having the head thereof bearing on the wire of the lamp harp frame and held in such bearing relationship by means of a metal cap bearing on the head of the stud and having pairs of opposed claws closed about the wire at opposite sides of the head of the stud the claws having sharp cornered ends impressed in the wire to confine the cap to a definite swiveling position on the wire. It will be seen that with the aforesaid swivel structure of Canadian Pat. No. 402,421 the head of the stud is forced into bearing contact with the wire of the lamp harp frame and causes the wire to bow slightly and the claws of the cap cut into the metal of the wire of the frame. The aforesaid swivel structure however is subject to a number of disadvantages and in particular it is found that due to the cutting action of the claws of the cap on the wire on repeated swiveling of the swivel structure to adjust the disposition of the lampshade that the swivel structure becomes progressively loose on the wire frame which is undesirable as the capability of the swivel structure to maintain the lampshade in any particular position for substantial periods of time progressively becomes smaller. Again, due to the cutting action of the claws of the cap on the wire of the frame the plating metal e.g. the brass is quickly removed from the wire at the contacts points of the claws with the wire thus exposing the base metal to the atmosphere which base metal tends to rust and this again is undesirable. Further as the swivel structure is made from a plurality of interacting metal parts, the cost of manufacture and the cost of assembly of the swivel structure on the wire is relatively large.

The present invention provides a swivel which is cheap and simple to manufacture, desirably by a simple molding technique, and is simple to attach to the wire frame of the lamp harp. Further, the swivel of the present invention does not disfigure to any significant extent the wire forming the frame of the lamp harp and further maintains a uniform tight grip on the wire frame even after repeated swiveling thereof on the wire frame.

According to the present invention therefore there is provided a swivel for use in mounting a lampshade on the wire frame of a lamp harp which swivel is formed of a resiliently flexible solid resinous material and comprises a base, a stud extending outwardly from one face of said base for clamping of a lampshade thereto and a channel extending across the opposite face of said base and dimensioned to accommodate the wire of said frame, the areas of said face on opposite sides of said channel being inclined towards each other whereby pressure applied to said inclined faces by clamping of the lampshade to said stud releasably closes said channel into tight gripping engagement with said wire accommodated therein. Preferably from practical considerations the channel is located directly opposite the stud.

In a particular embodiment of the present invention the base is in the form of a plate member having a pair of channel walls forming the channel and webs extending from the walls to the outer periphery of the plate member, which is desirably a disc, which webs enhance the effect of the pressure applied to the inclined areas of said one face for closing said channel.

It will be seen that by forming the swivel from a natural or synthetic solid resinous material such as polyamide, e.g. nylon; polyesters, polyolefins such as polytetrafluoroethylene or polyurethane the swivel can be readily molded in a one-piece unit in a simple manner at very low cost and due to the inclined surfaces on one face of the swivel from which the stud extends. in combination with the resilient flexibility of the resinous material it is possible to maintain the uniform and strong gripping engagement between the swivel and the wire forming the frame of the lamp harp merely by clamping the lampshade to the stud on the swivel. This gripping engagement, which is enhanced by providing a rough surface e.g. a splined surface on the wire in the area accommodated by the channel it will be readily seen is uniform irrespective of the amount of swiveling which has previously been effected by the swivel member on the wire of the lamp harp and further due to the relative softness of the resinous material as compared to the metal forming the wire of the lamp harp there is no disfiguration of the wire by the swivel.

The stud for clamping the lampshade to the swivel and thus on the lamp harp upon which the swivel is rotatably mounted, may take many forms and in one embodiment thereof comprises an externally threaded post for cooperation with an internally threaded nut. In another embodiment of the present invention the stud comprises a longitudinally split post having an enlarged portion remote from the base which provides for a snap-on attachment of the lampshade.

The present invention also includes the combination of said swivel with the wire frame of a lamp harp.

The present invention will be further illustrated by way of the accompanying drawing in which:

FIG. l-is an exploded side elevation of the swivel according to one embodiment of the present invention in combination with a lamp harp and lamp shade;

FIG. 2 is a side elevation of a swivel according to a second embodiment of the present invention; and

FIG. 3 is a plan view of the swivel of FIG. 2.

According to FIG. 1 it will be seen that only those portions of the lamp harp frame and the lampshade are shown which are necessary to illustrate the swivel of the present invention and the other parts of the lampshade and lamp harp frame are conventional.

The swivel, which is suitably formed from nylon, comprises a base 1 having a stud 2 in the form of an externally threaded post extending from one surface 3 thereof. On the opposite surface and located directly opposite the stud 2 is a pair of channel walls 4 defining a channel 5 which is dimensioned to accommodate the wire 6 of the frame of the lamp harp such that the swivel is rotatable on said wire 6.

The surface 3 of the base 1 is inclined upwardly in the areas on opposite sides of the channel 5 such that the areas are inclined suitably at about an angle of 5 to the horizontal towards each other. When pressure is applied to the surface'3 on clamping of the lampshade 7 to the swivel by locating the metal ring 8 of the lampshade over the post 2 and tightening the internally threaded nut 9 on the post 2, the inclined areas of the surface 4 are forced downwardly which closes the channel 5 on the wire 6. To enhance this closing of the channel 5 on the wire 6, webs 10 (see FIG. 2) extend between the base 1 and the channel walls 5. Further, to improve the grip of the walls 4 of the channel 5 on the area of the wire 6 as accommodated in the channel 5 the area of the wire 6 is splined at 11.

Referring specifically to FIGS. 2 and 3 the swivel is precisely the same as in FIG. 1 except that the stud 2 comprises a post 12 having a pair of splits 13 in cruciform configuration, the post 13 having lugs 14 at the top end thereof whereby the ring 8 of the lampshade 7 may be snapped into position on the swivel to effect clamping of the lampshade 7 on the swivel. This snap-on action also exerts pressure on the inclined surfaces to close the channel 5 into a gripping engagement with the wire 6.

We claim:

1. A swivel for use in mounting a lampshade on the wire of a wire frame of a lamp harp which swivel is formed of a resiliently flexible solid resinous material and comprises a base, a stud extending outwardly from one face of said base for attachment of a lampshade thereto and a channel extending across the opposite face of said base and dimensioned to accommodate the wire of said frame, said channel being located directly opposite said stud, the areas of said one face on opposite sides of said channel being inclined towards each other thereby pressure applied to said inclined surface by clamping of the lampshade to said stud releasably closes said channel into tight grippingengagement with said wire accommodated therein, said base being a plate member having a pair of channel walls forming said channel and webs extending from walls to the outer periphery of said plate member, which webs enhance the effect of the pressure applied to the inclined areas of said one face enclosing said channel.

2. A swivel as claimed in claim 1 in which the plate member is in the form of a disc.

3. A swivel as claimed in claim 1, in which is a one-piece molded article.

4. A swivel as claimed in claim 1, which the stud comprises an externally threaded post for cooperation with an internally threaded nut in clamping the lampshade thereto.

5. A swivel as claimed in claim 1 in which the stud comprises a longitudinally split post having an enlarged portion remote from said plate whereby to provide for snap-on attachment on said lampshade.

6. A swivel as claimed in claim 1, in which the inclined surfaces are at an angle of approximately 5 to the horizontal.

7. A swivel as claimed in claim 1, which is formed from nylon.

8. A swivel as claimed in claim 1 which is mounted on the wire frame of a lamp harp.

9. A swivel as claimed in claim 8 in which the portion of the wire accommodated by the channel is splined to enhance the grip by said channel on said wire. 

1. A swivel for use in mounting a lampshade on the wire of a wire frame of a lamp harp which swivel is formed of a resiliently flexible solid resinous material and comprises a base, a stud extending outwardly from one face of said base for attachment of a lampshade thereto and a channel extending across the opposite face of said base and dimensioned to accommodate the wire of said frame, said channel being located directly opposite said stud, the areas of said one face on opposite sides of said channel being inclined towards each other thereby pressure applied to said inclined surface by clamping of the lampshade to said stud releasably closes said channel into tight gripping engagement with said wire accommodated therein, said base being a plate member having a pair of channel walls forming said channel and webs extending from walls to the outer periphery of said plate member, which webs enhance the effect of the pressure applied to the inclined areas of said one face enclosing said channel.
 2. A swivel as claimed in claim 1 in which the plate member is in the form of a disc.
 3. A swivel as claimed in claim 1, in which is a one-piece molded article.
 4. A swivel as claimed in claim 1, which the stud comprises an externally threaded post for cooperation with an internally threaded nut in clamping the lampshade thereto.
 5. A swivel as claimed in claim 1 in which the stud comprises a longitudinally split post having an enlarged portion remote from said plate whereby to provide for snap-on attachment on said lampshade.
 6. A swivel as claimed in claim 1, in which the inclined surfaces are at an angle of approximately 5* to the horizontal.
 7. A swivel as claimed in claim 1, which is formed from nylon.
 8. A swivel as claimed in claim 1 which is mounted on the wire frame of a lamp harp.
 9. A swivel as claimed in claim 8 in which the portion of the wire accommodated by the channel is splined to enhance the grip by said channel on said wire. 